Frank W. Foss

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The splenic marginal zone is a site of blood flow, and the specialized B cell population that inhabits this compartment has been linked to the capture and follicular delivery of blood-borne antigens. However, the mechanism of this antigen transport has remained unknown. Here we show that marginal zone B cells were not confined to the marginal zone but(More)
The mechanisms involved in renal ischemia-reperfusion injury (IRI) are complex and appear to involve the early participation of bone marrow-derived cells. T lymphocytes participate in the pathogenesis of IRI. Sphingosine 1-phosphate (S1P) induces peripheral T cell depletion. Therefore, we hypothesized that S1P1 receptor activation protects kidney from IRI.(More)
Dietary isothiocyanates (ITCs) are electrophilic compounds that have diverse biological activities including induction of apoptosis and effects on cell cycle. They protect against experimental carcinogenesis in animals, an activity believed to result from the transcriptional induction of "Phase 2" enzymes. The molecular mechanism of action of ITCs is(More)
Dietary ITCs (isothiocyanates) prevent cancer and show other bioactivities in vivo. As electrophiles, ITCs may covalently modify cellular proteins. Using a novel proteomics screen, we identified MIF (macrophage migration inhibitory factor) as the principal target of nutrient ITCs in intact cells. ITCs covalently modify the N-terminal proline residue of MIF(More)
In the search for bioactive sphingosine 1-phosphate (S1P) receptor ligands, a series of 2-amino-2-heterocyclic-propanols were synthesized. These molecules were discovered to be substrates of human-sphingosine kinases 1 and 2 (SPHK1 and SPHK2). When phosphorylated, the resultant phosphates showed varied activities at the five sphingosine-1-phosphate (S1P)(More)
The synthesis of N-arylamide phosphonates and related arylether and arylamine analogues provided potent, subtype-selective agonists and antagonists of the five known sphingosine 1-phosphate (S1P) receptors (S1P(1-5)). To this end, the syntheses of phosphoserine mimetics-selectively protected and optically active phosphonoserines-are described. In vitro(More)
Trovafloxacin (Trovan) is a fluoroquinolone antibiotic drug with a long half-life and broad-spectrum activity. Since its entry into the market in 1998, trovafloxacin has been associated with numerous cases of hepatotoxicity, which has limited its clinical usefulness. Trovafloxacin possesses two substructural elements that have the potential to generate(More)
Phosphothioates may provide metabolic stability when compared to their phosphate counterparts, while retaining the potency and efficacy as agonists at sphingosine-1-phosphate (S1P) G-protein coupled receptors. Unlike their phosphate precursors, phosphothioate compounds with S1P-receptor profiles similar to that of FTY720, an emerging immunomodulator, were(More)
The study of electron transport through single molecules is essential to the development of molecular electronics. Indeed, trends in electronic conductance through organic nanowires have emerged with the increasing reliability of electron transport measurements at the single-molecule level. Experimental and theoretical work has shown that tunneling(More)
The mechanism for the hepatotoxicity of trovafloxacin remains unresolved. Trovafloxacin contains a cyclopropylamine moiety which has a potential to be oxidized to reactive intermediate(s) although other putative elements may exist. In this study, a drug model of trovafloxacin containing the cyclopropylamine substructure was synthesized. Chemical oxidation(More)